Diazotizable disazo dyes for cotton.



STATES PATENT OFFIfiE.

WILHELIVI HERZBEBG, 0F WILMERSDORF, AND WERNER LANGE, OF TEEPTDW, GER-MANY, ASSIGNORS TO ACTIEN GESELLSCHAFT. FllR ANILIN FABRIKATION, OF

BERLIN,

DIAZOTIZAIBLE DISAZO DYES FOB COTTON.

No Drawing".

To all Al 111M, it may concern:

Be it. known that we, VVILHELM Haaznnno and human Lalson, citizens ofthe German Empire, residing, respectively, at Wilmersdo-rf, near Berlin,Germany, and Treptow, near Berlin, Germany, have invented new and usefulImprovements in Diazotizable Disazo Dyes for Cotton, of which thefollowing is a specification.

We have found that new dyes corresponding to the formula:

where A and A stand for the residues of aromatic acids and X for aunivalent radical winch dye cotton generally yellow to orange .and mayhe further diazotizcd in substance or on the fiber and coupled withsuitable azo eonipo'uiuls are obtainable as follows: The disazo dyesderived from one molecular proportion of a symmetrical3.3-diaminodiarylurea of the benzene series and two molecularproportions of diazotized aromatic amino-acids are acidylized' in bothfree amino groups with a nitroarylcarboxylic acid halid whereupon thenitro groups are reduced.

Specification of Letters Patent. Application filed October 21, 1912.Serial No. 727,014;

Patented Nov. 1 1,1913.

The constitution of the dye is expressed by In the starting material oneor both molecules of the sulfanilie acid may be replaced by anotheramiuoacid, for instance metanilie acid, anisidin-sulfonie acid, achloroz'inilin-sulfonic acid, an amino-benzoic acid, anaphthylamin-sulfonic acid; also other 3.3-diaminodiaryhueas, forinstance 3.3- di:nninoditolylurca, 3.3 diamino 4.4.--dichlorodiphcnylurea may be used.

nitrobenzoyl chlorid may be employed.

The dyes obtained by the aforesaid process dye cotton directly yellow toorange. When diazotized on the fiber and developed with 2- naphtholthere are produced orange to red tints of good fastness to washing. v

The new dyes in the dry and pulverized shape of their sodium salts areorange powders easily soluble in water to a yellow solo tion not beingaltered by soda-lye or arm monia but from which hydrochloric acidseparates the yellow dye acids. They are practically insoluble inalcohol. From their red-brown solution in concentrated sulfuric acid onaddition of ice brown flakes are separated. By heating with zine-dustthe aqueous solution is decolorized, the dye be ing split, yielding thesame aromatic aminoaeids from which the diazo com-pounds were prepared,and a bis-aminoarylaeidylated 3.3.G.("-tetraaininodiarylurea.

Havingnow'described our invention what we claim is,

1. The herein-described process for the manufaetin'e of diazotizabledisazo dyes for cotton which consists in acidylizing with anitroarylcarboxylie acid halid the disazo Instead, of 3-nitrobenzoylchlorid, for example, the 4- diarylurea of the benzene series.

.Where A and A stand for the. residues of aromatic acids and X for aunivalent radical, these dyes by the reduction yielding aromaticamino-acids and symmetrical di-- aminodiaryldiacidyl 3.3.6.6 tetraemino-Gopies of this patent may be obtained for five cents ma es-o4 3. Theherein-described new diazotizeble dlsazo dye as sodium saltcorrespondlng to the formula:

and yielding by the reduction sulfanilic acid and symmetrical 3.3diaminodibenzoyl- 3.3.66-tetraaminodiphenylura,

In testimony whereof we have signed our names '59 this specification inthe presence of two subscribing witnesses.

WILHELM HERZBERG. WERNER LANGE.

Witnesses HENRY HAsrER, lVoLDnuAn HAUIT.

each, by addressing the Commissioner of Patents,

-= Washington, 30. 7.

